13 Plants Not To Grow Under A Willow Tree

The old willow tree with a thick strong trunk. The gentle spring leaves lit with the setting sun.

Willow trees make an excellent addition to the landscape. Their wispy branches and narrow leaves make them attractive yard trees. If you’re thinking about planting something under your willow tree, you may wonder what will and will not grow under a willow tree.

Plants that should not be planted under a willow tree include cotoneaster, mums, asparagus, leopard plant, dahlia, lupines, sedum, lilac, sage, peonies, forget-me-not, magnolia bush, and passion flower. These plants will either not grow or will struggle to flower under a willow tree.

Sprucing up the space under a willow tree adds plenty of ornamental value. Below, we’ll go over all the plants you can and can’t grow under a willow tree.

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Why Do Some Plants Struggle Under A Willow Tree?

Some plants do fantastic in the landscape, but as soon as you plant them under a willow tree they begin to struggle. What gives?

The conditions under a willow tree are:

  • Shady
  • High competition for water
  • High competition for nutrients
  • Possibility of flooding 
  • Fast-draining soil

Willow trees are known for being tolerant of flood conditions and they’re also typically located near a stream or river.

The reason willows love being near water is that their roots are shallow and spreading as opposed to those that penetrate deep into the soil. This makes it easier for the tree to obtain water and nutrients.

Water and nutrients aren’t the only determining factor of willow tree success. A study reported in the Journal of Environmental Management found that soil texture was the main factor when determining the success of black willow tree growth along stream banks.

Specifically, willow trees grow BEST in sandy soils that are gritty and well-draining. They do the worst in silt and clay soils that stay wet.

If a plant requires full sun, is a heavy feeder, requires a lot of water, or prefers to sit in constantly-wet soil, it will not do well under a willow tree.

Plants You Shouldn’t Grow Beneath A Willow Tree

According to Oregon State University, North America is home to about 90 different types of willow trees.

Each willow has its preference for soil, moisture level, and nutrient requirements. For the most part, willow trees prefer to grow near water in sandy soil and prefer full sun conditions.

Plants that are heavy feeders, require full sun, and/or prefer wet soil should not be planted under a willow tree.

Let’s check out all the plants you can cross off your list of what to grow under a willow tree.

Depending on what type of willow you have, you may want to choose different plants. Read more about this in our article about the differences between willows and weeping willows.

Cotoneaster

Bright red berries of bearberry cotoneaster, dammeri with green leaves

Cotoneaster is a shrub that should not be planted under a willow tree. Though it is pretty when it blooms and beneficial to wildlife, this evergreen is not meant to be paired with a willow tree.

Cotoneaster shrubs prefer full sun and do not do well in flooding conditions. We mention flooding conditions because many willow trees grow best in areas that occasionally flood.

In addition to sun and water requirements, cotoneaster grows too large to fit under a willow tree. According to North Carolina State University, cotoneaster will grow between 6 and 10 feet tall.

Chrysanthemum

When fall comes around and every other plant seems to be wilting away, mums bring in a flash of bright color to cheer us up.

With a height of only 1 to 3 feet tall, mums would fit perfectly under a willow tree. Unfortunately, there are a few obstacles that make mums a poor companion to willow trees.

Mums prefer full sun and will struggle in the shade of a willow tree. Besides their sun requirements, mums are also heavy feeders, meaning they require a lot of nutrients to thrive.

Being a heavy feeder means that mums will struggle when trying to compete with a full-grown willow tree for nutrients. They may also steal vital nutrients that would otherwise be used by the willow.

Annual mums could potentially survive under a willow tree for a single fall season but if you plan to make them perennials, they just won’t make it.

Asparagus

If you have a willow tree planted near your garden, there are a few vegetable plants that are going to struggle. Asparagus is one of them.

For how small asparagus is in stores, the plant is quite large. According to the University of New Hampshire, asparagus roots can reach down as far as 15 feet! For this reason alone, asparagus cannot grow well under or near a willow tree. 

In addition to its deep root system, asparagus also requires full sun, at least 8 hours a day. Asparagus are also heavy feeders and will struggle when competing against a willow tree for nutrients.

Leopard Plant

Ligularia przewalskii plant is often grown near water

Also known as ligularia, leopard plants have shiny, attractive foliage and produce yellow flowers in the fall.

This evergreen perennial can survive in partial shade and will struggle if given too much sun. While it’s not too picky about soil PH, leopard plants must be grown in consistently moist soil.

Willow trees may prefer to live near water sources, but they do not enjoy being consistently moist. For this reason, leopard plants are not a good fit for under a willow tree.

Dahlia

Dahlias are perennial flowering plants that produce beautiful big flowers in a range of colors in the summer and fall.

These eye-catching plants check off almost all the requirements to be planted under a willow tree. They prefer sandy, well-drained soil. They’re the appropriate height growing between 1 and 6 feet and they’re low-maintenance.

Unfortunately, dahlia’s prefer full sun and do best when they get at least 6 hours per day. That being said, dahlias would be a good choice to plant around a willow tree if it is far enough away to receive full sun.

Lupine

Lupines are adored by gardeners and homeowners for their unique shape and colorful flowers. They can be grown as annuals or perennials and will bloom at different times depending on the species.

Lupines prefer coarse-textured soils similar to willow trees, but they require full sun to thrive. Lupines are also heavy feeders that will compete with your willow tree for nutrients.

Another thing to note about lupines is that they will not tolerate alkaline soils (high PH). This makes them a bit tricky to plant unless you are willing to perform a soil test.

Sedum

Sedum is a groundcover plant that is often mistaken for a stone crop because it grows readily in rocky and stony areas. 

According to North Carolina State University, sedum is a perennial that requires full sun, making it a poor companion plant to a willow tree. Sedum also has a low tolerance for flooding and wet conditions, which can happen often around a willow tree.

Sedum has a lot of positive attributes that make it an attractive plant for the landscape. It blooms yellow flowers in late spring to early summer and requires very little soil.

Sedum requires little nutrients and water and only grows to about 9 inches in height, making it a great plant to fit in tight spaces.

Lilac

Good old lilacs have been around for years and are a favorite in the landscape for their fragrant flowers of pastel pinks, purples, and whites.

Lilacs are shrubs that can grow up to 15 feet tall if left unmaintained. Their height makes them a poor companion to a willow tree. 

In addition to their height, lilacs prefer full sun conditions. If they are planted in shade or partial shade they can develop powdery mildew.

Lilacs are better used as large border plants or hedge plants for a natural privacy fence.

Sage

Green sage plant herb leaves. Healing herbs, medicinal herbs.

Even though sage is an herb, it can be grown as a flower if you don’t plan on using it as a spice. If allowed to flower, sage produces purple-blue flowers.

According to the University of Wisconsin-Madison, sage does best in a sunny location and will struggle if placed in the shade. 

Peonies

Peonies are perennial plants that produce gorgeous flowers of red, white, yellow, pink, and purple. Peonies are long-lived and come back year after year.

There are a few reasons why peonies will not do well under a willow tree. One important fact is that peonies may not flower if they have to compete against willow roots for space, water, and nutrients.

An article in the New Zealand Journal of Forestry Science found that after just 9 months, willow tree roots can grow up to 18 feet laterally. With such fast growth, it’s no wonder they outcompete peonies and a host of other plants!

Additionally, peonies do BEST in full sun conditions. They can tolerate light shade, but will not bloom as many flowers and will struggle beneath the shade of a willow tree.

Forget-Me-Not

They’re named ‘forget-me-not’ for a reason! These short-lived perennials produce attractive pastel-blue flowers that you won’t soon forget.

Forget-me-nots can also be planted as an annual. They grow to about a foot, making them the right size to fit under a tree. However, these flowering plants will not thrive under a willow tree.

While forget-me-nots can survive with as little as 2 hours of sun per day, they prefer full sun and will not bloom as well when planted in the shade. Forget-me-nots also prefer consistently moist soil, which can be a problem when willow tree roots will suck up all the water.

Magnolia Bush

Magnolia is a large group encompassing over 100 different species. Some are trees while others are bushes. 

Here, we’ll be talking about the magnolia bush. This deciduous plant blooms in late winter and early spring, producing beautiful star-shaped flowers.

According to North Carolina State University, the magnolia bush prefers full sun and does best with consistently moist soils. 

Magnolia bushes will not survive under a willow tree if the tree is subject to flooding. Magnolia cannot tolerate flooding or extreme drought, making it a poor choice to plant under a willow tree.

Besides its inability to adapt to flood conditions, magnolia bushes can also grow over 20 feet tall. Unless you are dedicated to pruning it every year, it is too tall to fit under a willow tree.

Passion Flower

Purple and white passion flower found in the middle of the jungle

Passion flowers will give any landscape a tropical feel. Though these plants are native to Florida, they can grow in hardiness zones 6 through 11, which overlap with some of the willow tree’s territory.

These perennial vining flowers attract butterflies and hummingbirds, making them a perfect plant for a butterfly garden.

While passion flowers are tolerant of many different conditions and are considered easy to grow, they will struggle under a willow tree. They may even be harmful.

Passion flowers are vines that will grow as tall and wide as the object they are growing on. If planted under a willow tree, they may climb up the tree, which can stunt growth and choke out smaller branches. 

If you are willing to commit to constant pruning, passion flowers can be planted near willow trees as they are low-maintenance and can tolerate both shade and drought/flood conditions.

What Plants Can Live Under A Willow Tree?

Now that we know what can’t grow under a willow tree, let’s talk a little bit about what can grow under these stately trees.

Plants that grow under a willow tree will need to be low-maintenance, shade-tolerant, flood-tolerant, and adaptable to different soil types.

Some of the plants that will thrive under a willow tree include:

  • Solomon’s seal
  • Daffodils
  • Laminium
  • Lily of the valley
  • Lamb’s Ear
  • Sword Ferns
  • Hosta
  • Viola
  • Jack in the pulpit
  • Ajuga
  • Feverfew
  • Pulmonaria
  • Gooseneck loosetrife
  • Foxglove

These plants are low-maintenance and shade tolerant. Some are tolerant of flood conditions if your willow tree is planted on or near an area that sees occasional floods.

How To Help Plants Thrive Under A Willow Tree

The environment under a willow tree is too harsh for most plants, but there are quite a few exceptions! 

Shade-tolerant plants that are low-maintenance and require little water will thrive under a willow tree and will not over-compete for nutrients.

However, life is still rough trying to thrive beneath a tree. Here are some steps you can take to make sure your willow tree AND your plants stay happy and healthy:

  • Give plants enough water: Willow trees use A LOT of water per day. When you place another plant under a weeping willow, it may use some of the water your willow tree needs. Be sure to water your tree and new landscape plants frequently.
  • Apply fertilizer when necessary: Established willow trees do not need to be fertilized, but if you notice your tree looking a little droopy, it may be competing for nutrients with the plants you put beneath it. 

Apply a balanced 10-10-10 or 20-20-20 fertilizer to spruce up your willow tree and landscape plants.

  • Choose the right location: If the plant you’ve chosen does best in dense shade, pick a spot that receives the least sun. If it needs only partial shade, pick the place beneath your willow that receives the most sun.

You may also want to keep wildlife away from these plants and your tree. Specifically, snakes love willow trees. You can learn more about keeping snakes away from your willow tree here!

Alternative Options For Under A Willow Tree

If you’re not so sure about planting flowers beneath your willow tree, you have other options to make the space underneath look super nice yet remain low-maintenance.

Plant Grass Under Willow Trees

Willow tree by the pond with the mirroring on the surface

One option is to simply plant grass under your willow tree. A shade tolerant blend like Scotts Turf Builder Grass Seed Dense Shade Mix comes in a 7-lb bag. The seeds will sprout with just 3 hours of sun per day and will cover up to 1,750 square feet.

The same brand comes in a smaller 3-lb bag in case you only have a small area to cover under your willow tree.

One negative thing with grass is that it can attract snakes. If you are having this problem, you should give our article on 4 ways to keeps snakes away from willows a read.

Use Landscape Fabric And Decorative Stones

Another option is to strip away the existing grass under your willow tree and create a rocky landscape instead of a flower-themed landscape.

Place landscape fabric around the willow tree, making sure not to get too close to the trunk. ECOgardener’s Premium 5oz Pro Garden Weed Barrier Landscape Fabric comes in a 3’ x 50’ roll that can be cut to fit the shape under your willow tree.

Make sure to strip away the existing grass first so you can start with a blank slate. Once you place the fabric down, search for some decorative stones or pebbles that will look nice beneath your willow tree.

Midwest Hearth Natural Decorative Polished White Stones are an excellent choice. The soft white color will blend naturally with the environment while at the same time stand out as a stunning piece of landscape artwork!

For a more natural look, go with smooth river rocks in shades of brown, black, and grey. River rocks also go with the willow tree theme as they are found in or near water sources.

Mulch Around Your Willow Tree

Mulch can be beneficial to have around your landscape trees and plants. It helps keep plants warm in the winter and will retain moisture to prevent trees from drying out.

Instead of worrying about flowers, landscape fabric, or grass, you can simply mulch the area around your willow tree.

Keep the mulch at least 6 inches away from the trunk to avoid over-moisturizing the trunk, which can promote rot and cause fungus to develop.

Mulching will help keep weeds down for a season or two, but eventually, weeds will pop up between the mulching. You can prevent this by laying down landscape fabric under the mulch.

That’s All For Now!

Willow trees are amazing landscape specimens that thrive near waterways. Whether you have a massive weeping willow or a small Bebb willow, they certainly catch the eyes of all who pass!

Planting beneath a willow tree can be tricky. Plants that prefer full sun, are heavy feeders, or require lots of water will struggle under the dense shade of a willow tree.

Now, for a quick recap:

The plants you should not grow under a willow tree include:

  • Cotoneaster
  • Mums
  • Asparagus
  • Leopard plant
  • Dahlia
  • Lupine
  • Sedum
  • Lilac
  • Sage
  • Peonies
  • Forget-me-not
  • Magnolia bush
  • Passion Flower

All of these will struggle if planted under a willow tree. Instead, you’ll want to look for lower-maintenance plants that don’t mind sitting in the shade.

Best of luck on your willow tree journey!

References

Cao, Y., Repo, T., Silvennoinen, R., Lehto, T., & Pelkonen, P. (2011, January). Analysis of the willow root system by electrical impedance spectroscopy. Journal of Experimental Botany62(1), 351-358.

Doffo, G. N., Monteoliva, S. E., Rodriguez, M. E., & Luquez, V. M.C. (2016, October 03). Physiological responses to alternative flooding and drought stress episodes in two willows (Salix spp.) clones. Canadian Journal of Forest Research47(2), 174-182.

Larsen, M., & Trapp, S. (2006, February 07). Uptake of Iron Cyanide Complexes into Willow Trees. Journal of Environmental Science Technology40(6), 1956-1961.

Phillips, C.J., Marden, M. & Suzanne, L.M. Observations of root growth of young poplar and willow planting types. N.Z. j. of For. Sci. 44, 15 (2014).

Schaff, S. D., Pezeshki, S. R., & Shields Jr., F. D. (2003). Effects of Soil Condition on Survival and Growth of Black Willow Cuttings. Environmental Management31, 748-763. https://link.springer.com/article/10.1007/s00267-002-2909-y

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